My CAI does sound louder/beefier in the 2k-4k range.... 4k-5k sounds normal and anything above 5k has this awesome sounding wooshing sound... kinda like a turbine engine coming upto speed.

Kinda sounds like the noise you make when tell someone to SHHHHH but increasing in pitch slowly.

As for being cold? I don't really know.... our weather has been pretty frigid for a couple months now... and I just recently put it in, so I don't know what it sounds like when it's warm.